The ROMK potassium channel is present in mammalian urinary tract epithelia and muscle

David A. Spector, Qing Yang, Leonid Klopouh, Jie Deng, Edward J. Weinman, Deborah A. Steplock, Rajatsubhra Biswas, Marc F. Brazie, Jie Liu, James B. Wade

Research output: Contribution to journalArticle

Abstract

There is increasing evidence that mammalian urinary tract epithelial cells utilize membrane channels and transporters to transport solutes across their apical (luminal) and basalateral membranes to modify solute concentrations in both cell and urine. This study investigates the expression, localization, and regulation of the ROMK (Kir 1.1) potassium channels in rat and dog ureter and bladder tissues. Immunoblots of homogenates of whole ureter, whole bladder, bladder epithelial cells, and bladder smooth muscle tissues in both rat and dog identified ∼45- to 50-kDa bands characteristic of ROMK in all tissues. RT-PCR identified ROMK mRNA in these same tissues in both animal species. ROMK protein localized by immunocytochemistry was strongly expressed in the apical membranes of the large umbrella cells lining the bladder lumen and to a lesser extent in the cytoplasm of epithelial cells and smooth muscle cells in the rat bladder. ROMK protein and mRNA were also discovered in cardiac, striated, and smooth muscle in diverse organs. There was no difference in immunoblot expression of ROMK abundance in bladder homogenates (whole bladder, epithelial cell, or muscle cell) or ureteral homogenates between groups of rats fed high- or low-potassium diets. Although the functional role of ROMK in urinary tract epithelia and smooth muscle is unknown, ROMK may participate in the regulation of epithelial and smooth muscle cell volume and osmolality, in the dissipation of potassium leaked or diffused from urine across the epithelial cell apical membranes or tight junctions, and in net or bidirectional potassium transport across urinary tract epithelia.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Renal Physiology
Volume295
Issue number6
DOIs
StatePublished - Dec 2008

Fingerprint

Urothelium
Potassium Channels
Urinary Bladder
Muscles
Epithelial Cells
Potassium
Smooth Muscle
Ureter
Smooth Muscle Myocytes
Cell Membrane
Urine
Dogs
Messenger RNA
Membranes
Membrane Transport Proteins
Striated Muscle
Tight Junctions
Urinary Tract
Ion Channels
Cell Size

Keywords

  • Calponin
  • Epithelial sodium channel

ASJC Scopus subject areas

  • Physiology
  • Urology

Cite this

Spector, D. A., Yang, Q., Klopouh, L., Deng, J., Weinman, E. J., Steplock, D. A., ... Wade, J. B. (2008). The ROMK potassium channel is present in mammalian urinary tract epithelia and muscle. American Journal of Physiology - Renal Physiology, 295(6). https://doi.org/10.1152/ajprenal.00022.2008

The ROMK potassium channel is present in mammalian urinary tract epithelia and muscle. / Spector, David A.; Yang, Qing; Klopouh, Leonid; Deng, Jie; Weinman, Edward J.; Steplock, Deborah A.; Biswas, Rajatsubhra; Brazie, Marc F.; Liu, Jie; Wade, James B.

In: American Journal of Physiology - Renal Physiology, Vol. 295, No. 6, 12.2008.

Research output: Contribution to journalArticle

Spector, DA, Yang, Q, Klopouh, L, Deng, J, Weinman, EJ, Steplock, DA, Biswas, R, Brazie, MF, Liu, J & Wade, JB 2008, 'The ROMK potassium channel is present in mammalian urinary tract epithelia and muscle', American Journal of Physiology - Renal Physiology, vol. 295, no. 6. https://doi.org/10.1152/ajprenal.00022.2008
Spector, David A. ; Yang, Qing ; Klopouh, Leonid ; Deng, Jie ; Weinman, Edward J. ; Steplock, Deborah A. ; Biswas, Rajatsubhra ; Brazie, Marc F. ; Liu, Jie ; Wade, James B. / The ROMK potassium channel is present in mammalian urinary tract epithelia and muscle. In: American Journal of Physiology - Renal Physiology. 2008 ; Vol. 295, No. 6.
@article{a4b4b823e49b4be5a5dd6e903da37b3a,
title = "The ROMK potassium channel is present in mammalian urinary tract epithelia and muscle",
abstract = "There is increasing evidence that mammalian urinary tract epithelial cells utilize membrane channels and transporters to transport solutes across their apical (luminal) and basalateral membranes to modify solute concentrations in both cell and urine. This study investigates the expression, localization, and regulation of the ROMK (Kir 1.1) potassium channels in rat and dog ureter and bladder tissues. Immunoblots of homogenates of whole ureter, whole bladder, bladder epithelial cells, and bladder smooth muscle tissues in both rat and dog identified ∼45- to 50-kDa bands characteristic of ROMK in all tissues. RT-PCR identified ROMK mRNA in these same tissues in both animal species. ROMK protein localized by immunocytochemistry was strongly expressed in the apical membranes of the large umbrella cells lining the bladder lumen and to a lesser extent in the cytoplasm of epithelial cells and smooth muscle cells in the rat bladder. ROMK protein and mRNA were also discovered in cardiac, striated, and smooth muscle in diverse organs. There was no difference in immunoblot expression of ROMK abundance in bladder homogenates (whole bladder, epithelial cell, or muscle cell) or ureteral homogenates between groups of rats fed high- or low-potassium diets. Although the functional role of ROMK in urinary tract epithelia and smooth muscle is unknown, ROMK may participate in the regulation of epithelial and smooth muscle cell volume and osmolality, in the dissipation of potassium leaked or diffused from urine across the epithelial cell apical membranes or tight junctions, and in net or bidirectional potassium transport across urinary tract epithelia.",
keywords = "Calponin, Epithelial sodium channel",
author = "Spector, {David A.} and Qing Yang and Leonid Klopouh and Jie Deng and Weinman, {Edward J.} and Steplock, {Deborah A.} and Rajatsubhra Biswas and Brazie, {Marc F.} and Jie Liu and Wade, {James B.}",
year = "2008",
month = "12",
doi = "10.1152/ajprenal.00022.2008",
language = "English (US)",
volume = "295",
journal = "American Journal of Physiology",
issn = "0363-6135",
publisher = "American Physiological Society",
number = "6",

}

TY - JOUR

T1 - The ROMK potassium channel is present in mammalian urinary tract epithelia and muscle

AU - Spector, David A.

AU - Yang, Qing

AU - Klopouh, Leonid

AU - Deng, Jie

AU - Weinman, Edward J.

AU - Steplock, Deborah A.

AU - Biswas, Rajatsubhra

AU - Brazie, Marc F.

AU - Liu, Jie

AU - Wade, James B.

PY - 2008/12

Y1 - 2008/12

N2 - There is increasing evidence that mammalian urinary tract epithelial cells utilize membrane channels and transporters to transport solutes across their apical (luminal) and basalateral membranes to modify solute concentrations in both cell and urine. This study investigates the expression, localization, and regulation of the ROMK (Kir 1.1) potassium channels in rat and dog ureter and bladder tissues. Immunoblots of homogenates of whole ureter, whole bladder, bladder epithelial cells, and bladder smooth muscle tissues in both rat and dog identified ∼45- to 50-kDa bands characteristic of ROMK in all tissues. RT-PCR identified ROMK mRNA in these same tissues in both animal species. ROMK protein localized by immunocytochemistry was strongly expressed in the apical membranes of the large umbrella cells lining the bladder lumen and to a lesser extent in the cytoplasm of epithelial cells and smooth muscle cells in the rat bladder. ROMK protein and mRNA were also discovered in cardiac, striated, and smooth muscle in diverse organs. There was no difference in immunoblot expression of ROMK abundance in bladder homogenates (whole bladder, epithelial cell, or muscle cell) or ureteral homogenates between groups of rats fed high- or low-potassium diets. Although the functional role of ROMK in urinary tract epithelia and smooth muscle is unknown, ROMK may participate in the regulation of epithelial and smooth muscle cell volume and osmolality, in the dissipation of potassium leaked or diffused from urine across the epithelial cell apical membranes or tight junctions, and in net or bidirectional potassium transport across urinary tract epithelia.

AB - There is increasing evidence that mammalian urinary tract epithelial cells utilize membrane channels and transporters to transport solutes across their apical (luminal) and basalateral membranes to modify solute concentrations in both cell and urine. This study investigates the expression, localization, and regulation of the ROMK (Kir 1.1) potassium channels in rat and dog ureter and bladder tissues. Immunoblots of homogenates of whole ureter, whole bladder, bladder epithelial cells, and bladder smooth muscle tissues in both rat and dog identified ∼45- to 50-kDa bands characteristic of ROMK in all tissues. RT-PCR identified ROMK mRNA in these same tissues in both animal species. ROMK protein localized by immunocytochemistry was strongly expressed in the apical membranes of the large umbrella cells lining the bladder lumen and to a lesser extent in the cytoplasm of epithelial cells and smooth muscle cells in the rat bladder. ROMK protein and mRNA were also discovered in cardiac, striated, and smooth muscle in diverse organs. There was no difference in immunoblot expression of ROMK abundance in bladder homogenates (whole bladder, epithelial cell, or muscle cell) or ureteral homogenates between groups of rats fed high- or low-potassium diets. Although the functional role of ROMK in urinary tract epithelia and smooth muscle is unknown, ROMK may participate in the regulation of epithelial and smooth muscle cell volume and osmolality, in the dissipation of potassium leaked or diffused from urine across the epithelial cell apical membranes or tight junctions, and in net or bidirectional potassium transport across urinary tract epithelia.

KW - Calponin

KW - Epithelial sodium channel

UR - http://www.scopus.com/inward/record.url?scp=57349124522&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=57349124522&partnerID=8YFLogxK

U2 - 10.1152/ajprenal.00022.2008

DO - 10.1152/ajprenal.00022.2008

M3 - Article

VL - 295

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6135

IS - 6

ER -